Heel binding

ABSTRACT

A release heel binding for use with skis and ski boots which utilizes a torsion bar type means for restraining the boot, permitting some upward movement of the heel, and means for positively releasing the ski boot after the heel has lifted a predetermined amount. The unit is adjustable so that the necessary force required to release the boot can be changed to make the binding usable across a wide range of operating conditions. The torsion bars provide for high energy storage to return the binding when lower than release loads have been encountered. The unit can be reset either by stepping into the binding, or by a manual reset movement of a lever.

United States Patent [15] 3,659,866 Petersen May 2, 1972 [54] HEELBINDING Primary ExaminerBenjamin Hersh Assistant Examiner-Robert R. Song[72] Inventor. Paul S. Petersen, Minnetonka, Minn. An0mey Dugger,Peterson Johnson & westman [73] Assignee: Sports Technology, Inc.,Edina, Minn.

57 ABSTRACT [22] Filed: Nov. 14, 1969 1 App]. No.: 876,788

A release heel binding for use with skis and ski boots which utilizes atorsion bar type means for restraining the boot, permitting some upwardmovement of the heel, and means for positively releasing the ski bootafter the heel has lifted a predetermined amount. The unit is adjustableso that the necessary force required to release the boot can be changedto make the binding usable across a wide range of operating conditions.The torsion bars provide for high energy storage to return the bindingwhen lower than release loads have been encountered. The unit can bereset either by stepping into the binding, or by a manual reset movementof a lever.

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Patented May 2, 1972 3,659,86

3 Sheets-Sheet 5 INVEN'IOR. PAN/l 5. PETERSEN HEEL BINDING BACKGROUND OFTHE INVENTION 1. Field of the Invention The present invention relates toheel bindings for use with skis and ski boots.

2. Prior Art The commercially available heel bindings on the marketwhich provide for a release of the heel utilize compression springs forresisting movement of the heel and an overcenter toggle arrangement forrelease when the lifting force on the heel has exceeded a predeterminedamount. The problem is that the amount of upward movement of the bootpermitted is usually quite low. Compression springs require a great dealof space so the springs are kept short in bindings to keep them contactand therefore the spring movement cannot be very great. Where overcenteror near center linkage holding action is relied upon, the location ofthe pivot points for the release linkage has to be very precise or elsethe unit can lock in holding position and not release when desired.

It is desirable to permit the heel to lift off the ski under skiingconditions to absorb shock loads, and store energy during the lifting sothat the unit will return the boot heel firmly against the ski when thehigh loads have been removed unless a full release force is reached.This permits a setting which will let the ski boot move up when highlift forces are encountered but will always control the boot and returnit securely to the ski except under loads high enough for release.

Additionally, it is desired in many instances to hold the ski boot downunder a resilient load or spring load onto the ski so that there is nolooseness in the binding itself.

None of the prior art devices fulfill these requirements to the fullextent necessary and still keep the cost down. Also, the use of thetorsion bars in the present device in combination on a heel binding forskis presents a unique way of getting high energy storage to permitupward movement of the heel, and subsequent returning of the heel to itsheld position without full release.

SUMMARY OF THE INVENTION The present invention relates to a releasableheel binding utilizing torsion bars for holding the heel of a ski bootin place, and for energy storage when the boot raises under high loads.The binding is constructed so that the amount of force necessary torelease the binding is adjustable. The release action is a positivemechanical release that physically moves levers into a released positionafter the heel has lifted a desired amount from the ski. The heelbinding is made so that the heel is held securely without increase inforward pressure throughout a heel lift to one half to three quarters ofan inch from the ski, and when released, the heel cup or holding memberactually exerts an ejecting action on the boot to positively release theboot.

In addition, the unit is made of simple stamped or formed parts that donot require complex machining or casting.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top plan view of a heelbinding made according to the present invention;

FIG. 2 is a side elevational view of the device of FIG. 1;

FIG. 3 is a side elevational view of the device of FIG. 1 showing theunit in a full released position from upward force on the ski;

FIG. 4 is a sectional view taken as on line 4-4 in FIG. 2;

FIG. 5 is a sectional view taken on substantially the same line as FIG.4 but showing the unit in a fully released position at the point ofrelease by the ski, and corresponding to the position of FIG. 3;

FIG. 6 is a sectional view taken as on line 6-6 in FIG. 4; and

FIG. 7 is a side elevational view showing the device after the unit hasbeen released, or when the hand release lever has been moved to amanually released position.

DESCRIPTION OF THE PREFERRED EMBODIMENT A release heel bindingillustrated generally at 10 is mounted onto a mounting member 11 that isfastened to a ski 12 in a suitable manner. The mounting member 11 hasupturned edges forming channel shaped tracks into which a main frame 13is slidably mounted. The frame 13 can be adjusted in fore and aftpositions, with a screw arrangement as shown, which also holds thebinding in proper position. The frame is used for supporting thecomponents of the assembly. The frame can be adjusted as desired andwill be held in place.

The frame 13 is used for mounting a heel cup or heel holding member 14of the heel binding. The heel cup 14 has a lip member 15 that engagesthe groove in the rear heel portion of the ski boot 16 in the usualmanner. The heel cup as shown has a forward surface that inclinesdownwardly and rearwardly from this lip 15 so as to not interfere withthe boot heel in normal skiing position.

The heel cup is held in place through the use of a pair of links and thelinks control the movement of the heel cup. There is a first, U-shapedupper link or lever 17. The upper link 17 has a top plate 18 anddepending legs 19,19. The legs 19,19 extend outside of oppositeuprightly extending support walls 22 of the frame 13. The link 17 ispivotally attached to these support walls with suitable pivot pins sothat it pivots about an axis 23. The forward portions of the link 17 arepivotally mounted about a pin axis 24 to the upper part of the heel cup14. The heel cup is also held in place with a pair of lower links orlevers 25. The lower links 25, as shown, have offset rear portions, andthe front portions are pivotally mounted at 26 to opposite sides of thelower part of the heel cup. The lower links 25 extend on the inside ofthe side walls 22 of the frame 13, and at the rearward ends of the linksextend upwardly, and the rearward ends are pivotally mounted with across pin 27 to coupling links 28. The pin 27 for pivotally mounting thelinks 25 and 28 together is slidably mounted in slots 29 defined in setportions of the side walls 22,22 of the frame. The slots 29 are made inan indented part of the side walls so that they have an edge surface onwhich the pin 27 slides along the slots as the coupling links 28 and thelower links 25 are actuated. One cross pin 27 is used for joining thetwo sets of links 28 and 25.

The coupling links 28 are each pivotally mounted at their opposite endswith pins 30 to the side legs 31,31 of a U-shaped closing and releaselever assembly 32. The lever 32 is pivoted to frame 13 as at 34 and isformed so that the legs 31 will fit outside of the side support walls 22of the frame 13 when it is in its down position as shown in FIG. 4. Theside support wall 22 is cut away to provide clearance for the pinconnection between the coupling links 28 and the walls 31 of the closingand release lever. The pins 30, as shown, are at right angles to theplane of the coupling links 28 so that they can pivot freely. The pinconnection to the slanting legs 31 of the coupling lever is made so thatthis can be done.

A pair of relatively light tension coil springs 33, 33 are positionedbetween the lower links 25 and the lever 32, to cause the lever torotate about its pivot axis 34. The springs are connected to the lever32 at position between the pivot axis 34 and the pins 30. The springs 33are used for providing a force tending to put the lever towards itsseated positioned as shown in FIG. 4 when resetting the lever, and alsofor holding the lever in up" position as shown in FIG. 7. The force fromsprings 33 goes overcenter to hole lever 32 up when it is fully raised.

The movement of the upper link 17 about its pivot 23, and consequentlythe movement of the heel cup 14 upwardly, is restained and controlledthrough the use of a torsion bar assembly illustrated generally at 38.The torsion bar assembly 38, as shown, is a rod bend into a U-shape. Thebar assembly has a pair of side legs 39,39 joined together adjacent thebase end of the unit. The legs 39 each form a separate torsion barmember. At the forward end of the unit, each of the torsion bars 39 hasan actuating lever 40 and 41, respectively. The lever 40 is positionedahead of the lever 41, and extends inwardly or in other words toward theopposite torsion bar 39 from the bar to which it is attached. The lever41 is positioned to the rear of the lever 40 and extends toward theopposite torsion bar 39 from which it is attached. The torsion bars 39are positioned adjacent the edges of the ski and the spring lever extendtransversely across the ski to greatly conserve space. The outer ends ofthe levers 40 and 41 are flattened, as shown, and a pair of tensionlinks 42 and 43, respectively, are connected to the torsion bar levers40 and 41. The tension links in turn are mounted over a hanger orcontrol nut 44. The nut 44 is supported for sliding movement along thetop wall 18 of the link 17. The top wall has a slot 45 defined therein,and the nut 44 has an upper section 46 that has wing-like projections onopposites sides of the slot 45 that ride against the top surface of thewall 18 and prevent the nut from passing down through this slot. The nuthas a lower portion 47 below wall 18, and the lower portion 47 also haslateral projections forming recesses 48,48 on opposite sides thereofinto which the upper ends of tension links 42 and 43 can be hooked. Anadjusting screw 50 is rotatably positioned through a rear wall 49 oflink 17 and is threadably mounted through the lower portion 47 and thenut 44. The screw 50 is held from axial movement in the wall 49 andcontrols the movement of the nut back and forth in the slot 45 definedin the top wall 18 of the upper link 17. Thus, as the heel cup raises,the link 17 is lifted and the bars 39 are stressed in torsion.

The torsion bars 39 are elongated members than can absorb torsionstress. The rear ends of these bars are restrained by the frame and bythe curved portion of the U. Individual elongated members could be usedand restrained at the rear end of the bonding with suitable levers orlugs.

The movement of the nut 44 along the slot 45 determines the leverage ofthe link 17 acting on the torsion bars 39 when the heel 16 of the skiboot tends to lift in upward direction against the lip of the heel cup.The nut movement will in turn provide adjustability to adjust the forcethat is necessary to lift the heel cup so the heel binding can be usedfor children, juniors or adults.

The heel binding of the present invention is made so that it willtolerate shock loads. The torsion bars will store energy if the heel islifted to return the heel to position flat against the top part of theski when the load is reduced or removed. lt can be seen that as the heeltends to lift up, the heel cut will cause the upper link 17 to pivotabout the pivot points 23 and 24 while the lower link 25 also pivotsupwardly. The movement of the link 17 will cause the tension links 42and 43 to lift the outer ends of lever 40 and 41 upwardly and therebycause torsion stress in the torsion bars or legs 39 of the torsion barassembly 38. This creates a restraining force that is relatively high,without having a bulky compression or tension spring. The torsion barscan store large amounts of energy without requiring a large volume ofspace for movement.

Until the binding is tripped, it will cause the heel to be returned tothe ski when the force tending to lift the heel has been removed. Thusshock loads in skiing will be accommodated by this heel binding withoutany difficulty. As shown in FIGS. 2 and 4, the heel cup 14 will bepermitted to pivot upwardly without tripping the binding until the upperedges of the lower links 25 lift the pins connecting the connecting link28 to the closing and release lever 32 to an on center" position withpin 27 and pivot 34. This is shown in dotted lines in FIG. 4. Anymovement of the heel cup upwardly to this position will be permitted andthe binding will return if the load is removed. However, if the upwardload is increased so that the torsion bars are stressed in torsionsufficiently high to permit further movement of the lower link 25 beyondthis position, the upper edge of the lower link will lift pins 30 andlever 32 to a point where the axis of pin 30 goes past a line betweenthe axis of pin 27 and pivot 34.

The force from the heel on lip 15 will be tending to pull link 25forwardly. Thus the links 28 will be pushing forwardly on pins 30. Assoon as pin 30 goes overcenter the force from links 28 will throw thelever 32 upwardly and pin 27 will be permitted to slide forwardly inslots 29. The force on lip 15 causes this action. The forward movementof links 25 thrusts the lower portions of the heel cup forwardly toposition shown in FIGS. 3 and 5. The lower end of the heel cup movesforwardly to more or less eject the boot from the binding and fullyrelease the skier in time to prevent any damage to the skiers leg.

As soon as the heel 16 is released, the torsion bars will snap thetension links and the links 17 and 25 down to a position Where the linksare in their at rest position, but the release lever 32 will remain up.The light springs 33 go overcenter to hold the release lever in itsraised position. The position is shown in FIG. 7. This is the manuallyreleased position of lever 32 and the binding as well as the releaseposition after the foot has been ejected. A small forwardly extendingtab can be placed onto the bottom edge of the heel cup so that when theunit is to be reset, the heel of the boot can be stepped down againstthe tab and this will move the link 25 rearwardly so that the pin 27will slide rearwardly in the slots 29 and link 28 will pull the lever 32back downwardly. The springs 33 go overcenter again and exert enoughforce to flip the lever 32 down into its closed position so that anautomatic step-in is provided.

The use of the torsion bars for a release heel ski binding permitsstorage of high energy levels in a compact space and finds wide usage inpermitting this storage of energy. The travel of the torsion bar leversbefore release can be adjusted and the amount of energy stored can beadjusted. The movement of the nut 44 controls the amount of force thatis necessary for releasing by changing the leverage on the upper link17. The vertical distance of movement of the heel cup prior to releaseremains the same because this is determined by the position of the linksand levers.

Operation is enchanced by the use of the torsion bars which can store agood deal of energy over a substantial distance of movement of the bootso that the ski boot heel can be permitted to lift without full releaseand return to a flat position on the ski as desired and also by theability to change the leverage or mechanical advantage to a fixed forcespring rather than changing the spring force to change the setting.

The heel cup, as shown in FIG. 5, can be made adjustable by utilizing aframe 52 that has the main portion of the cup mounted thereon and ascrew 53 for adjusting it up and down to provide for different types ofboots. The cup is made so with the upper link 17 and the lower link 25operating the cup will follow a path which permits the heel of the bootto move up without exerting any substantial forward force on the boot.The heel cup does not move away from the boot heel either, so the bootwill not be released prematurely. With proper adjustment, the initiallifting force of the heel can be a desired fraction of the full releaseforce. There can be a preset downward force on the heel. The heelbinding does have a positive release after the boot has moved upwardly.The links 25 and 28 and lever 32 are positive actuators for the releasemechanism. This is different than relying on conventional near centerholding action of links. In the present device the positioning of thepivot points is not particularly critical for getting holding force. Thelinks here are actually physically released by movement of one of thelinks itself so that if the locking pivot points are slightly shiftedbecause of manufacturing variations, the danger of locking the bindingin holding position is not present. The release is positive and relatedto movement of linkages restrained by the torsion springs, rather thanbeing related to force exerted on the holding links. The amount of forcenecessary to trip here is determined only by the torsion bars and thesetting of the leverage adjustment.

The binding unit also permits a lever action insertion of the foot, ifthe step-in action is not desired. The ability to close the lever fromposition as shown in FIG. 7 manually or with the tip of a ski pole isimportant because in some cases it is difficult to step into a binding,particularly in powder snow. The heel cup can be positioned so that evenwith step-in action, the heel cup will slightly tension the torsion barswhen it is in its holding position. A low closing pressure on the lever32 can produce a large clamping pressure at the heel cup because of themechanical advantages involved. For example, when the lever 32 goesovercenter in a closed position, the mechanical advantage of this levertending to raise the upper link slightly when the lip hits the heel isquite great. The springs 33 provide this force on lever 32.

As shown in FIG. 1, the top wall 18 can have suitable markings on it sothe setting of the adjusting nut and thus the setting of the binding canbe easily determined.

High energy storage is possible in a limited space with torsion bars.The bars can be stressed higher during operation than a coil spring dueto the Wahl factor which limits operation stress in a coil spring.Energy storage, the important function in the present device, is afunction of the square of the stress so higher stress levels give muchhigher energy storage. There is no large sweep volume necessary inactuating a torsion bar as the only moving part is the actuating lever.The torsion bars are also easy to attach to the movable portions of thebinding. Torsion bars which are actuated in only one direction as herecan be preset or prestressed in a known manner which allows them tooperate at an apparent higher stress level resulting in further savingsof weight and spring volume. Approximately one-third as such steel isrequired in a torsion bar as compared to a coil spring to obtain thesame energy storage. A coil spring have the equivalent energy sotragecapacity to torsion bars 39 would be much too large to be generallyconsidered for usage in a ski binding.

The ability to change the mechanical advantage of the linkage means thatthe adjustment does not require tightening or loosening the torsionbars. Thus the bars dont change in force range, but the leverage of thebiasing force changes. The full torsion bar bias force is usable whetherthe unit is set for a child or adult, so the binding action is uniformacross the range of movement of the heel cup but the actual forcerequired to lift the cup changes in level.

The torsion bars are retained under shoulders at the edges of frame 13.These shoulders are cut away so they don t interfere with operation oflevers 40 and 41.

What is claimed is:

1. In a release binding for use between a ski boot and a ski, a frame,means for mounting said frame to a ski, boot retainer means adapted toengage a portion of a ski boot, means mounting said boot retainer meansto said frame to permit movement of said boot retainer means relative tosaid ski to a boot releasing position, and means to resist movement ofsaid boot retainer means toward boot releasing position comprising anelongated bar member mounted with respect to said frame and having alongitudinal axis extending in a first direction with respect to saidski, means restraining said bar member from rotating with respect tosaid frame, actuator means attached to said bar member at spacedlocation from said restraining means, and means coupling said actuatormeans and said boot retainer means whereby the actuator means is rotatedabout the longitudinal axial of said bar member and said bar member isstressed substantially only in torsion about said longitudinal axis whensaid boot retainer means moves toward boot releasing position relativeto said ski.

2. In a release binding for use between a ski boot and a ski, a frame,means for mounting said frame to said ski, boot heel retainer meansadapted to engage the heel portion of a ski boot, means mounting saidboot heel retainer means to said frame to permit movement of said bootheel retainer means relative to said ski, said means mounting said bootretainer means comprising a first link means between said boot heelretainer means and said frame, said first link means being pivotallymounted to said frame about a generally horizontal axis and connected tosaid boot heel retainer so that upon upward movement of said boot heelretainer said first link means will pivot, and means to resist upwardmovement of said boot heel retainer means comprising an elongated barmember having a longitudinal axis extending in a first direction withrespect to said ski, means to restrain said bar member from rotatingwith respect to said frame, and means between said first link means andsaid elongated bar member to cause said elongated bar member to bestressed in torsion to resist movement of said first link means and saidboot heel retainer means with respect to said ski.

3. The combination as specified in claim 2 wherein said means betweensaid link means and said elongated bar member includes adjustable meansto permit changing the effective point of application of force from saidelongated member on said link means with respect to the pivotalconnection of said link means to said frame.

4. The combination as specified in claim 2 wherein said heel retainer ismounted to the frame with two link means, a second link means includingactuator means, said actuator means being positioned so that uponmovement of said heel retainer upwardly, portions of said second linkmeans contacts said actuator means and causes a releasing action of saidheel retainer with respect to the heel of a ski boot.

5. The combination as specified in claim 4 wherein said second linkmeans includes a release lever, means acting between said actuator meansand a portion of said release lever whereby said actuator means movessaid release lever to release position after said second link means hasmoved a predetermined amount.

6. A ski boot binding for use between a ski boot and a ski comprising aframe, means for mounting said frame to a ski, boot retainer means,means mounting said boot retainer means on said frame so as to permitboot releasing movement of said boot retainer means relative to saidski, and spring means to resist movement of said boot retainer meansrelative to said ski comprising torsion bar means, said torsion barmeans comprising at least one elongate member mounted on said bindingand having a longitudinal axis extending in a first direction along saidski, lever means fixedly connected to said elongated member adjacent oneend thereof and extending laterally therefrom, means acting between saidbinding and elongated member to restrain the opposite end of saidelongated member from rotating about its longitudinal axis, and meansacting between said lever and said boot retainer means whereby movementof said boot retainer means relative to the ski will cause said lever tostress said elongated member in tor sion about its longitudinal axis.

7. The combination as specified in claim 6 wherein linkage means areprovided for mounting said boot retainer means to said frame, andwherein said means connecting said lever to said boot retainer meansincludes an adjustable member mounted on said linkage means, and meansto move said adjustable member so as to change the effective leverage ofthe force exerted by said torsion bar means on said boot retainer means.

8. The binding as specified in claim 6 wherein said boot retainer meanscomprises a heel retainer movable upwardly from the ski to a releaseposition, and linkage means mounting said heel retainer means to saidframe including a link connected to the heel retainer and pivoted tosaid frame rearwardly of the heel retainer, and means coupling saidlever means to said link whereby movement of said link about its pivotwill move said lever means to change the torsional stress in saidelongated member.

9. A heel binding for use between a ski boot and a ski comprising aframe, means for mounting said frame to a ski, heel retainer meansmounted on said frame so as to permit upward movement of said heelretainer means relative to said ski, and torsion bar means to resistmovement of said heel retainer means relative to said ski in upwarddirection, said torsion bar means comprising two elongated membersmounted on said binding and extending generally in direction of thelength of said ski, separate lever means fixedly connected to saidelongated members adjacent first ends of said elongated members, saidlever means of each elongated member extending transversely to the skiand to the elongated members, means to restrain second ends of saidelongated members with respect to said ski, and means between said levermeans and said heel retainer means whereby movement of said heelretainer means upwardly from the ski will cause said lever means tostress said elongated members in torsion.

10. The combination as specified in claim 9 wherein linkage means areprovided for mounting said heel retainer means to said frame, andwherein said means connecting said levers to said heel retainer meansincludes an adjustable member mounted on said linkage means, and meansto move said adjustable member so as to change the effective leverage ofthe force exerted by said torsion bar means on said heel retainer means.

11. The combination as specified in claim 10 wherein said linkage meansincludes a pivoting lever, said lever being pivoted to said heelretainer means and to said frame, and said adjustable means includes anut threadably mounted onto a screw, said nut being movable along saidlinkage means between the pivots of said lever.

12. The combination as specified in claim 10 wherein said linkage meansincludes upper and lower links, said upper and lower links beingpivotally mounted between the heel retainer means and the frame atopposite ends thereof, the pivot points of said upper and lower linksbeing positioned so that as said heel retainer means moves upwardlytoward a release position the heel retainer means does not substantiallychange the force on the ski boot held therein in direction along thelongitudinal axis of the ski.

13. The heel binding of claim 9 wherein said elongated members arespaced apart in transverse direction and said lever means on one of saidelongated members extends toward the other elongated member.

14. The heel binding of claim 13 wherein said elongated members arejoined together at the ends thereof opposite said levers to form a Ushaped structure.

15. The combination as specified in claim 9, and release means for saidheel retainer means including linkage means mounting said heel retainermeans to said frame and movable against the action of said torsion barmeans, and a releasing element movable to position to release saidrelease means after said heel retainer means has lifted a predeterminedamount from said ski.

1. In a release binding for use between a ski boot and a ski, a frame,means for mounting said frame to a ski, boot retainer means adapted toengage a portion of a ski boot, means mounting said boot retainer meansto said frame to permit movement of said boot retainer means relative tosaid ski to a boot releasing position, and means to resist movement ofsaid boot retainer means toward boot releasing position comprising anelongated bar member mounted with respect to said frame and having alongitudinal axis extending in a first direction with respect to saidski, means restraining said bar member from rotating with respect tosaid frame, actuator means attached to said bar member at spacedlocation from said restraining means, and means coupling said actuatormeans and said boot retainer means whereby the actuator means is rotatedabout the longitudinal axial of said bar member and said bar member isstressed substantially only in torsion about said longitudinal axis whensaid boot retainer means moves toward boot releasing position relativeto said ski.
 2. In a release binding for use between a ski boot and aski, a frame, means for mounting said frame to said ski, boot heelretainer means adapted to engage the heel portion of a ski boot, meansmounting said boot heel retainer means to said frame to permit movementof said boot heel retainer means relative to said ski, said meansmounting said boot retainer means comprising a first link means betweensaid boot heel retainer means and said frame, said first link meansbeing pivotally mounted to said frame about a generally horizontal axisand connected to said boot heel retainer so that upon upward movement ofsaid boot heel retainer said first link means will pivot, and means toresist upward movement of said boot heel retainer means comprising anelongated bar member having a longitudinal axis extending in a firstdirection with respect to said ski, means to restrain said bar memberfrom rotating with respect to said frame, and means between said firstlink means and said elongated bar member to cause said elongated barmember to be stressed in torsion to resist movement of said first linkmeans and said boot heel retainer means with respect to said ski.
 3. Thecombination as specified in claim 2 wherein said means between said linkmeans and said elongated bar member includes adjustable means to permitchanging the effective point of application of force from said elongatedmember on said link means with respect to the pivotal connection of saidlink means to said frame.
 4. The combination as specified in claim 2wherein said heel retainer is mounted to the frame with two link means,a second link means including actuator means, said actuator means beingpositioned so that upon movement of said heel retainer upwardly,portions of said second link means contacts said actuator means andcauses a releasing action of said heel retainer with respect to the heelof a ski boot.
 5. The combination as specified in claim 4 wherein saidsecond link means includes a release lever, means acting between saidactuator means and a portion of said release lever whereby said actuatormeans moves said release lever to release position after said secondlink means has moved a predetermined amount.
 6. A ski boot binding foruse between a ski boot and a ski comprising a frame, means for mountingsaid frame to a ski, boot retainer means, means mounting said bootretainer means on said frame so as to permit boot releasing movement ofsaid boot retainer means relative to said ski, and spring means toresist movement of said boot retainer means relative to said skicomprising torsion bar means, said torsion bar means comprising at leastone elongate member mounted on said binding and having a longitudinalaxis extending in a first direction along said ski, lever means fixedlyconnected to said elongated member adjacent one end thereof andextending laterally therefrom, means acting between said binding andelongated member to restrain the opposite end of said elongated memberfrom rotating about its longitudinal axis, and means acting between saidlever and said boot retainer means whereby movement of said bootretainer means relative to the ski will cause said lever to stress saidelongated member in torsion about its longitudinal axis.
 7. Thecombination as specified in claim 6 wherein linkage means are providedfor mounting said boot retainer means to said frame, and wherein saidmeans connecting said lever to said boot retainer means includes anadjustable member mounted on said linkage means, and means to move saidadjustable member so as to change the effective leverage of the forceexerted by said torsion bar means on said boot retainer means.
 8. Thebinding as specified in claim 6 wherein said boot retainer meanscomprises a heel retainer movable upwardly from the ski to a releaseposition, and linkage means mounting said heel retainer means to saidframe including a link connected to the heel retainer and pivoted tosaid frame rearwardly of the heel retainer, and means coupling saidlever means to said link whereby movement of said link about its pivotwill move said lever means to change the torsional stress in saidelongated member.
 9. A heel binding for use between a ski boot and a skicomprising a frame, means for mounting said frame to a ski, heelretainer means mounted on said frame so as to permit upward movement ofsaid heel retainer means relative to said ski, and torsion bar means toresist movement of said heel retainer means relative to said ski inupward direction, said torsion bar means comprising two elongatedmembers mounted on said binding and extending generally in direction ofthe length of said ski, separate lever means fixedly connected to saidelongated members adjacent first ends of said elongated members, saidlever means of each elongated member extending transversely to the skiand to the elongated members, means to restrain second ends of saidelongated members with respect to said ski, and means between said levermeans and said heel retainer means whereby movement of said heelretainer means upwardly from the ski will cause said lever means tostress said elongated members in torsion.
 10. The combination asspecified in claim 9 wherein linkage means are provided for mountingsaid heel retainer means to said frame, and wherein said meansconnecting said levers to said heel retainer means includes anadjustable member mounted on said linkage means, and means to move saidadjustable member so as to change the effective leverage of the forceexerted by said torsion bar means on said heel retainer means.
 11. Thecombination as specified in claim 10 wherein said linkage means includesa pivoting lever, said lever being pivoted to said heel retainer meansand to said frame, and said adjustable means includes a nut threadablymounted onto a screw, said nut being movable along said linkage meansbetween the pivots of said lever.
 12. The combination as specified inclaim 10 wherein said linkage means includes upper and lower links, saidupper and lower links being pivotally mounted between the heel retainermeans and the frame at opposite ends thereof, the pivot points of saidupper and lower links being positioned so that as said heel retainermeans moves upwardly toward a release position the heel retainer meansdoes not substantially change the force on the ski boot held therein indirection along the longitudinal axis of the ski.
 13. The heel bindingof claim 9 wherein said elongated members are spaced apart in transversedirection and saiD lever means on one of said elongated members extendstoward the other elongated member.
 14. The heel binding of claim 13wherein said elongated members are joined together at the ends thereofopposite said levers to form a ''''U'''' shaped structure.
 15. Thecombination as specified in claim 9, and release means for said heelretainer means including linkage means mounting said heel retainer meansto said frame and movable against the action of said torsion bar means,and a releasing element movable to position to release said releasemeans after said heel retainer means has lifted a predetermined amountfrom said ski.